This invention concerns a gate for a lamp, particularly for illuminating rectangular objects, having a holding element defining a light-passage opening which is mountable on the lamp and four gate wings mountable on the holding element about the light-passage opening for defining a gate opening.
From a prospectus, "dedolight" of the Dedo Weigert Film GmbH, which was published in July of 1989, a gate for a lamp having four gate wings is known. Two of the gate wings are main wings which are mounted on opposite sides of a light-passage opening of the holding element to be pivotal about parallel first pivot axes which extend parallel to corresponding main-wing surfaces. The other two gate wings are side wings which are mounted at opposite sides of the light-passage opening, on the holding element, to be pivotal about parallel second pivot axes which extend substantially perpendicular to the first pivot axes. The second pivot axes extend parallel to planes of their corresponding side wing surfaces. It follows that by means of the four gate wings a rectangular gate opening can be shaped which, by means of pivoting the gate wings, can be varied in size. Such a gate is particularly suitable for illuminating in film and TV applications.
When illuminating a rectangular object, such as, for example, a painting in a museum, it is desired to only illuminate the object itself. Known gates are not suitable for this because they do not produce very precisely shaded silhouettes, so that their formed light right angles have "rabbit ears". If an employed lamp is placed in a flood position a slight barrel shaped (bowed) distortion is brought about along the straight length edges of the gate wings. Because of this, it is not possible to form a straight edge. Further, when illuminating paintings in museums it is usual to employ a lamp so that a light beam therefrom is directed downwardly at an angle of approximately 45.degree.. When a rectangular gate opening is used, this results in a trapezoidal image being created on the illuminated object. Because of this, when a rectangular object is illuminated, not only the object itself is illuminated.
An object of this invention is to provide, in an uncomplicated manner, a gate for a lamp that makes possible a sharply bordered illumination of rectangular objects.